Automatic dam.



PATENTBD FEB. 26, 1907.

F. GAMAGNI. AUTOMATIC DAM.

lAPPLIOATION FILED APR.17, 19 0 6.

l I-IIN iiiidll" j Ari/ THE NoRRlsPErERs cm, WASHINGTON, n. c

UNITED STATES PATENT OFFICE.

AUTOMATIC DAM.

Specification of Letters Patent.

Patented Feb. 26, 1907.

Application filed Avril 17, 1906. Serial No 312,246.

To ail whom, it may concern:

Be it known that I, FRANCESCO CAMAGNI, engineer, residing at Asti, Italy, Corso Alfieri 69, a subject of the King of ltaly, have invented certain new and useful Improvements in Automatic Dams.

The object of the present invention is a rotatable dam to be employed in channels of rivers; and it is designed to maintain the water above the dam at a practically constant height automatically Without substantially affecting the flow of the water or creating dangers or inconvenience when the waters are high or overflow.

The invention is illustrated in the accompanying drawings, in which- Figure 1 shows in sectional elevation the simplest manner of constructing the improved automatic dam. Fig. 2 shows in sectional elevation a combination of the form shown at Fig. 1, with a movable weight; and Fig. 3 shows in sectional elevation a further modification of Fig. 1.

Referring first to Fig. 1, a; y is the riverbed, A B the highest water-level, and M N the lowest level, below which the water must not be allowed to fall. On the shores of the river or channel, upon convenient piers 4, standards 3 are fixed, carrying pivots 2, about which the dam is rotatable. The dam is made of two boards 1 21, joined to each other so as to form a triangular vessel a b 0, having the apex a on the bed of the river and the base I) c flush with level M N. Through the upstream-wall 1 of the vessel are made holes 5, allowing water to enter and fill up the vessel, which is so proportioned that the weight of water contained therein counterbalances the pressure exerted by the outside water upon the upstream-wall 1 of the vessel when the level of the water is at M N.

l/Vhen the water rises above level M N, the pressure against the upstream-board 1 of the vessel increases, so that said vessel is lifted, as shown at a b c in dotted lines, a portion of the water contained in the same overflowing along'the line transverse to the point 0, partially emptying the vessel. The vessel becomes consequently lighter, increasing its tendency to be lifted, so that when the level of the water reaches the maximum height A B the dam is almost or entirely open and offers practically no opposition to the free passage of the stream.

When it is desired to maintain the waterlevel practically constant at the maximum the bottom of the same heightthat is, when it is desired that the levels A B and M N should practically coincide-the combinations shown at Figs. 2 and 3 are preferred as being more prompt and efficient.

According to the arrangement of Fig 2, the size of the vessel is so proportioned that its weight, including the Weight of the water contained therein, is not sufficient to counterbalance the pressure of the outside water against wall 1, and an additional weight or ballast 8 is provided which can travel on guides 7, carried by'a supporting-framework 6, fixed to the dam. The guides 7 are shaped, as shown in the drawings, in such a manner that upon the vessel being tilted about the axis 2 the weight 8 travels back toward the axis, and consequently its moment about said axis is reduced. The several parts are so proportioned that when the apex (1 reaches the level M N the weight 8 has traveled beyond the axis 2 and nearly counterbalances the dead-weight of the dam. In case when the dam is of very small dimensions the traveling weight 8 would do by itself without employing any vessel; but the employment of a vessel such as described is to be preferred in the generality of cases.

In the arrangement of Fig. 3 the dam itself is made in the same way as in Fig. 1. Near at 10 a yielding or flexible pipe 9 is attached, havinga dischargemouth S, which is maintained constantly at the level M N, said discharge-mouth being connected by a cord 18 to a drum 16, mounted on a shaft 13, supported by standards 12 12 on the banks, and carrying a pulley 14, from which is supported a weight 19. The shaft 13 carries also a tapered drum 15, connected to one end of a cord 17, the other end of which is attached to the drum. The weight 19 is so proportioned as to counterbalance the dead-weight of the dam, which is in turn of such a size that the water contained in the vessel a t c in its lowest position counterbalances the pressure ofthe outside water against the wall 1. The drum 15 is tapered for the reason that the leverarm of the dead-weight of the dam about its axis of rotation 2 varies when the dam is lifted, and the cord 17 winding itself up around the drum 15, follows a conical spiral line on the drum and varies accordingly its lever-arm about the axis '13, so that the initial conditions of equilibrium are maintained. When the water tends to rise above the level M N,

the dam is lifted, the weight 19 descends, causing the pulley 14 and shaft 13 to rotate, whereby the drum 16 is also rotated and the cord 18 unwound, the discharge-mouth S being in this manner maintained at the level M N, so that the water inside the vessel is rapidly discharged and brought to the level M N. By employing such arrangements it is possible to maintain the water in the river or channel exactly at the predetermined level M N.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I clain is 1. An automatic dain for continuously maintaining the water in a river or the like at a constant level comprising a vessel having holes therein which communicate with the upstream and pivoted to turn about an axis above the highest level of the water, said darn being inclined so as to have its lower end downstream relatively to the axis substantially as described.

2. An automatic dam for continuously maintaining the water in a river or the like at a constant level comprising a vessel having holes therein communicating with the l l a l i a l l l upstream and pivoted to turn about an axis above the highest level of the water, said dam being inclined so as to have its lower end downstream relatively to the axis, and having an additional weight or ballast arranged to travel toward the axis of rotation when the dam is raised, substantially as described.

3. An automatic dam for continuously maintaining the water in a river or the like at a constant level comprising a vessel having holes therein communicating with the upstream and pivoted to turn about an axis above the highest level of the water, said dam being inclined so as to have its lower end downstream relatively to the axis, and having an opening near its bottom, a pipe connected with said opening and discharging its contents at a fixed predetermined height, and a weight on the shore, counterbalancing the dead-weight of the dam.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

FRANCESCO CAMAGN I.

l/Vitnesses:

MARIO CArnooro, GOTTARDO O. PIRoNI. 

